Trailer brake control



Feb. 6, 1940.

A. H. ACE El AL Y TRAILER BRAKE CONTROL Filed May 8. 1937 Patented eds; 1940 v iUN-l'lfE D. STATES 11 m OFFICE} Tasman BaAKncon'moL Arch- 11. Ace and Loyd n. nan-1mm, Bowling 1 Green, Ohio I :Ap plication May s; weasel-m1 No. 141,436'

This invention relates to trailer brake controls, and is more particularly directed to an actuating means for hydraulic brakes used in connection with a towed vehicle.

The primary object of the invention is the pro vision of adjustable means to control" brakes on reference being had to the-accompanying draw-.

ing, in which- Figure 1 is"a fragmentary, diagrammatic, perspective view of a typical installation shown in connection. with-a frame of a towed vehicle; Fig;

30 2 is a longitudinal section taken online 2-2 of v Fig. 1, andJE'Ig. 31s a fragmentary section on line 3-4 of Fig. 2. Referring to the drawing, the present inv is shown inv connection with a trailer ha a frame Lprovlded with a forwardly extendingyoka including parallel towing bars 2.and I tovwhich a hitch member 4 may be fastened in any suitable manner. .The hitch member is'providedwith an elongated slot iwhich is adaptedto-receive a hi iqhing pin'i-iastened toza iliged towing plate'l" on the towing. vehicle. 4

r The. braking system shown is operated and includes theusualwheel cylinders 8,;connected bybranch lines! and main line Ill toHa-mastercylinder ll. The mastercyHnder is formed in a housing llwhichfimay' received between two depending side plates I2, 13 fixed to the towln yoke ofthe rramel.

A aerate operating piston I5 is in the master; cylinder I l and is directly connected .to a tactuating rod li extending iorwardly from the housing l2 and connected intermediate'the' ends of a lever arm l'l whichilatter is pivotally mounted on. a ;pin it between the dependins 5 plates; I

The. piston is moved by a compound lever in-.'

elu in aforwardly extending arm 20 adapted to bear against the fixed pin Band 9. depending a'rm 22 pivotally mounted between the-plates l! as at 24. The force is transmitted iromthedepending lever arm 22 through anadiustable member including a roller contact 25 and a yokell'slidably mounted about the pivoted arm I! and adjustable longitudinally thereof.

u as shown in Fig. 3, the yoke 2i s im-s im tion "the crowding force is released.

inwardly extending fingers 28 received between the threads of a worm 30 which is journalled in the arm I] and controlled at its upper end-by a vsuitable handle 32. f It will be seen that as the I worm 30 is-turned, the positionof' the yoke" 5 vabout thearm II will .be varied vertically and the contact wheel 25 will be moved closer to, or farther from, the pivot point 240! the force transmitting arm 2 2.-

In the n r rtne" towed vehicle it tends to crowd it againstthe towing car so that the towing yoke moves forwardly with relation. to the fixed pin 6 carried on the towing car; The

force transmitting lever arms 20 and 22 are; 1 therefore, moved rearwardly about the pivot pin- 15 24 and in turn force the contact-2i and its yoke 26 rearwardly to swing the am I'l about its pivot point It and thus move the piston l5. rearwardly in the master cylinder II; This places the fluid in'the braking lines 9-to the wheel "cylinders 8 30 under pressure and causes an actuation of the I brakes. I

In order that the "braking force maybe varied inaccordance with the load requirements of the towed vehicle, it is necessary to provide means to 25 vary the force applied to the brakes by changing a the torce applied to the piston l5. For this reason, the adjustable contact- 25 is provided so that the action of the brakes may be varied by chang ing the point of application 01' the operating force to the pivot. point 24, It will be seen that a given crowding movement of the towing vehicle will have a greater effect on the piston II as thecontact 25 is moved away from the pivot 24, and that the brakingaction may he softened by moving the contact 25 closer to the pivot '24 or downwardly on thearm I! in Fig. 2, a

. A suitable coil spring as may be provmeuo. return the parts totheir normalpositionwhen I "In order that the trailer may heQmoved in" a reverse direction ,without the actuation oi the brakes, as is' necessary incertain maneuvers, .it

is; necessary tomrovide means totemporarily re- IMSQLilhfiIZIQHGI'bIB-HDG sys em. To. accomplish e5 1 this, the housing {2 may be provided with an upwardly extending passage .40 communicating with themain line l0 and; cylinder ll of thevbr'aking system and adapted to be, placed in controlled communication through a passage 42 with a fluid 50.

reservoir 44 in the housing I2. The passage 42 is 'pr'ei'er ably controlled by a spring Dressed piston typevvalye .i-llwhich be moved 'out of its normalposition by a-solenoid 48:1,When the-valve I 48 is actuated by the solenoid; 44am! l4' 42 will be thrown in open communication so that fluid may pass through the cylinder II to the resepvoir 44 instead of-to the wheel cylinders 8 where it would normally act on the trailer brakes.

When, the reversing force is released, it is necessary to provide means-which will quickly restore the fluid to the cylinder I l to the trailer braking system from'the reservoir 44. To this end a ball check valve 50 normally held in seating position 0 "by a coilspring 52- 'may'be .provided.- It will be seenthat as'suction occurs in the passage 40 due to a forward movement of the piston IS, the ball check valve 50 will be unseated and fluid will flow freely from the reservoir 46 through the passage 40 through the cylinder H. The filling maybe accentuated by placing the cylinder H in direct communication with the, reservoir. by a small passage 54 so that as the piston l5 movestorwardly of' the passage, fluid will flow by gravity from the reservoir to themaster cylinder.

. The solenoid la-may be operated by any suitable circuit closer associated with the towin vehicle, either in the transmission thereof or adjacent the drivers seat. The circuit closer is diagrammatically illustrated at S in Fig. 1. It will be seen that the present invention provides a simple and 'emcient means to control the braking force applied to the hydraulic braking system of a towed vehicle, and further provides an efilcient means to vary the braking action in accordance wlth-, the load carried by the trailer. While ,the invention has been described in connection with a particular assembly, it should be readily appreciated that various changes may ,be-made in the form and disposition of the partswithout departing fromthe spirit of the appended claims.

What we claim is:

1i. A brakeactuating device for towed vehicles.

having hydraulic brakes including, a master cylinder and a piston operating therein, a lever arm connected to said piston and pivoted at one end, actuating means abutting afixed point one. towing vehicle and carried by the towed vehicle, and an adjustable contact point disposed between said lever arm. and said actuating means.

2. A brake actuating device for towed vehicles having hydraulic brakes including, a master cylinder and a piston operating therein, a lever arm connected to said piston and pivoted at one and; actuating means abutting a fixed point on a towing vehicle and carried by the towed vehicle,

a. fluid reservoir adjacent said master cylinder,-

and means toplace said fluid reservoir and master cylinder in open communication whereby movement of said piston will force fluid into the reservoir instead of actuating the hydraulic brakes. i

3. A brake actuating device for towed vehicles including, brake operating means, a lever arm connected to said operating means and pivoted at one end and adapted to exert pressure on said operating means, means to actuate the lever arm from the towed vehicle, and means to vary the pressure exerted by the lever arm including an adjustable fulcrum carried by the lever arm and adapted to transmit force from said actuating means.

4. A brake actuating device for towed vehicles including, brake operating means, a lever arm connected to said operating means and pivoted at one end and adapted to exert pressure on said operating means, means to actuate the lever arm irom the towed vehicle, and means to vary the pressure exerted by theJeIer arm. including an adjustable fulcrum disposed between said lever arm and said actuating means.

' 5'. A brake actuating device for towed vehicles having. hydraulic brakes including, a master cylinder and a piston operating therein, a lever arm connected to said piston and pivoted at one end, means to actuate the lever arm from the towed vehicle, and an adjustable contact point disposed between said lever arm and said actuating means. I

6. A brake actuating device for towed vehicles having hydraulic brakes including, a master cylinder and a pistonoperatingtherein, a lever arm connected to said piston and pivoted at one end means to actuate the lever arm from the towing. vehicle, a fluid reservoir adjacent said master cylinder, and means to place said fluid reservoir and master cylinder in open comactuate said brakes including a cylinder and a piston therein, communication means between said cylinder and. said hydraulic brake actuating means, liquid in said cylinder and said communieating means, means actuated by movement of said trailer toward said automobile to compress the fluid in the cylinder, at liquid receiving chamber, a passage between said chamber and said cylinder, a valve in said passage," and electrical meansto actuate said valve to permit flow of for. a vehiclertralin, including a set of fluid-operatedbrakes, a cylinder and fluid operating piston therein, means. for imparting movement to said piston and fluid to operate said brakes an electricallyloperated valve for permitting the escape of fluid from said cylinder for rendering said movement ineffective, and a switch for operating said valve.

v ARCH H. ACE.

LOYD R. 

